Toy airplane construction



Jan. 9, 1940. N. E. WALKER TOY AIRPLANE CONSTRUCTION Filed Sept. 4, 1934 2 Sheets-Sheet l Jan. 9, 1940. N. E. WALKER TOY AIRPLANE CONSTRUCTION Filed Sept. 4, 1934 2 Sheets-Sheet 2 Patented Jan. 9, 1940 UNITED STATES PATENT OFFICE 6 Claims.

The principal object of my invention is to provide a toy airplane of the same general type as is disclosed in my copending application for patent entitled Toy airplane, which issued as 5 Patent No. 1,972,117, dated September 4, 1934.

Toy airplanes of this character are usually provided with an elastic band motor adapted to rotate a propeller and to fly said toys substantial distances through the air. It is necessary, therefore, that said toys be of light weight so as to be capable of flying such distances and yet be substantially sturdy and substantially made so as to withstand the shock of landing. A material suitable for this purpose is balsa wood, which is 15 adapted to provide a proper finish, is suillciently stiff, and is reasonable in price. Balsa wood, however, has the disadvantage of being fragile and brittle. It is desirable, also, that said toy 20 airplanes simulate standard models of commercial airplanes and thus must be provided with tubular bodies and the wings must be given a proper amount of camber and dihedral angle so that said planes have good flying characteristics.

To attain these ends, it is necessary that the ,5 sections of wood making up the bodies and wings of said toy airplanes be curved and the fragile character of the wood needs reinforcement without much added weight, so that said airplane can be flown many times without injury.

80 I have improved said general type of airplane by making said body and wing portions of thin sections of balsa wood permanently distorted to proper shape and the tubular bodies thereof are made of a plurality of gores butt-fitted and 35 secured together. To prevent crushing inwardly, I provide annular frame rings interiorly of the body and to maintain the desired cross-section I arrange a reinforcing rim at the forward end of the body which encircles and lies within the edges thereof. Said reinforcing material also serves to prevent longitudinal crushing due to the tension of the elastic motor and also tends to prevent the gores from splitting. All of these features are accomplished without adding sub- 45 stantially to the overall weight of said devices.

The wings are made of sections similarly permanently distorted and the ends thereof are reinforced by a material having high tensile strength such as bias-cut binding tape. gaid 50 frame rings lying interiorly of the body also serve to reinforce the point of joinder between the landing gear and the body and also reinforce the body laterally at each side of the wings. The landing gear also is made yieldable with repect 56 to the body. and preferably resiliently with regard thereto, so as to minimize breakage at a point adjacent the Joining connection between said landing gear and the body.

Further details of construction of said toy airplane are hereinafter described with reference to the accompanying drawings, in which:

Fig. 1 is a side elevation of a toy airplane embodying my invention;

Fig. 2 is a fragmentary plan view thereof Fig. 3 is a smaller scaled front elevation of said toy airplane;

Fig. 4 is a diagrammatic illustration of the manner in which the body is made of longitudinally arranged gores butt-glued together about an internal framework; I

Fig. 5 is a diagrammatic section taken on the line 5-5 in Fig. 2 showing the manner in which the binding materials is mounted upon the ends of the wings; I

Fig. 6 is a more or less diagrammatic section taken on the line 6-6 in Fig. 1 illustrating the manner in which the reinforcing nose ring is placed upon the airplane body;

Fig. 'l' is a diagrammatic section illustrating the manner in which the various parts of said airplane are permanently distorted; and

Fig. 8 is a sectional view taken on the line 88 in Fig. 1 taken through the point where the landing gear is joined to the body of the airplane.

A toy airplane of this character is provided with a tubular body a preferably constructed of a series of longitudinally arranged gores a, a2, a3 and a. The number of gores is unimportant and the number is determined by the construction of the particular model. In some cases it is desirable to have two gores and in some others a different number of gores. In the particular embodiment, the body is built up of four gores. As is illustrated, the four gores represent the four circumferential quarters of the body,' two gores on each side constituting one-half of said body, the two halves being left and right-handed thus producing a circular section when joined together. 45

The rear end of the body terminates at a point and at said point the rudder b and the tail sections 0 are fltted in place. At the other end, the body terminates in a section of substantial diameter and to strengthen said section and to prevent 50 splitting and to maintain the circular section of the entire body, I arrange a nose ring d, U-shaped' in section, one leg lying externally of the body and the other internally thereof, and the intermediate portion overlying the end. Said ring is is preferably glued or otherwise secured to said body.

Internally I preferably arrange two frame rings e, which are annular in form and have a substantial factor of stiffness. The gores making up the body are arranged about said rings and thus the rings not only tend to arrange said gores in proper original relation, but tend also to give the entire body stiffness against crushing.

Intermediate said rings and overlapping them slightly are slots J, through which the wing element g extends. The slots I extend through the body portions and the latter are quite fragile, and thus the rings e give additional body support to said wings. The rings also are made of balsa wood or similar material and the grain of the wood runs circumferentially of the body and thus does not tend to split at the ends because said slot, as it overlie and extends through the rings, does not extend through endgrain material. On the other hand, the gores are made of sections of material in which the grain runs longitudinally of the body and thus without said rings the gores would tend to split. The rings are preferably glued or otherwise secured to the gores and the adhesion between the parts serves mutually to strengthen and support the entire structure.

Landing gear comprising struts h, wheels 2', and so-called wheel pants 1' are secured at both sides of the longitudinal centerline of the body. Said struts preferably'are yieldingly and resiliently mounted to the body so as to minimize the shocks to which the body is subjected upon landing. Thus said struts are made in two sections and said sections are pivotally secured to each other as at la. The portions-of the struts which overlie each other are connected by a coiled spring I mounted in cupped portions m in each of the strut sections 77..

The forward ring registers with the point of joinder between the struts and the body to strengthen and reinforce the latter against crushing. That is, the struts terminate in flanged portions overlying the body and said ring.

The propeller n may include a spinner portion 12' to which the propeller blades are secured, not only to facilitate construction of said toy, but also to simulate standard practice in airplanes. Extending through said spinner is the propeller shaft 0, which preferably terminates in an eye 0' to serve as the point of engagement with a winding device. Said shaft extends through a hardwood plug p, arranged on the noserin'g d and said hardwood plug is extended to serve as a bearing for the propeller shaft.

As was pointed out in the'co-pending application for patent to which reference has been made, the propeller shaft does not extend along the longitudinal center-line of the body, but is provided with so-called negative angle, and thus the extended bearing is necessary for maintaining said angle. Upon the inner end, said propeller shaft is also formed into another eye 02, to which one end of the elastic band motor q can be secured. At the tail end of said airplane body, an aperture r is formed, which aperture is surrounded by a collar s to strengthen said aperture and to prevent a tail hook it from crushing said body. The tail hook t constitutes the other securing device for the elastic band motor and is provided with an eye t to which said end of the band motor can be secured.

The wing element 9' is provided with camber and with dihedral angle substantially its entire length, but in the central portion it is flattened as at g, so that it will correspond laterally to the slots ,f. If the wing is made of continuous camber, the slots tend to eliminate the camber for a substantial distance outwardly towards the tips thereof, which affects the flying characteristics of said airplane. By flattening the central portion, however, this vflattening effect is substantially eliminated and the wing is also automatically located longitudinally with respect to movement in said body. The tips of the wing element are preferably provided with sections of reinforcing material u, which extend about said tips and which is secured thereto. I have discovered that a desirable material is bias-cut reinforcing or binding tape, which is glued to the tips of the wings and extends about the and grain portions of said wings. It is not necessary to arrange said reinforcing material about the entire marginal portions of the wing, although it may be done if desired. If only a portion of the wing is provided with reinforcing material, the remainder can be painted with a strip corresponding to the width of the overlying portions of the reinforcing material, so that the strips of reinforcing material and paint will produce a decorative border about the entire wing structure.

The various wing and body portions are made of balsa wood and they are permanently distorted to their desired form in heated dies '0. The sections of wood are wetted or are steamed and are placed in said dies 1; under substantial pressure. If the sections to be formed are merely wetted, which is a desirable practice, they are placed in the heated dies and pressed. The dies are hot enough so that the water upon the surfaces of the section of wood to is first formed to steam and then dried by evaporation. This method not only forms the sections of material to the desired shape, but also if it isdesired to slit the portions and overlap them to produce sharp curves, the heat and pressure will cause said sections of wood to be firmly secured to each other in the desired form without the use of supplementary adhesive material. This feature is particularly desirable when the body portions are made of but two gores and the forward end of said body is narrowed to a section of small diameter, while the central portion of said body is of substantially larger diameter.

I claim:

1. A toy airplane comprising an entire body of sheet balsa wood permanently warped to predetermined form, said body being more or less cylindrical and comprising a plurality of abutting longitudinal sections constituting gores of said cylindrical body.

2. A toy airplane comprising an entire body of sheet balsa wood permanently warped to predetermined form, said body being more or less cylindrical and comprising a plurality of abutting longitudinal sections press formed to the desired contour constituting gores of said cylindrical body.

3. A toy airplane comprising an entire body of permanently pre-formed sheet balsa wood, said body being more or less cylindrical and comprising a plurality of abutting longitudinal sections press formed to the desired contour, mounted upon an interior frame work and constituting gores of said cylindrical body. I

4. A toy airplane comprising an entire body of sheet balsa wood permanently warped to predetermined form, said body being more or less cylindrical and comprising a plurality of abutting longitudinal sections mounted upon an interior frame work and provided with a circumferential binding member arranged at one end thereof U- shaped in section and straddling said end.

5. In a' toy airplane having a straight slot for receiving a wing, an integral wing element made of sheet balsa wood premanently warped to predetermined form in which the ends thereof are given camber and the central portion is more 10 or less flat.

6. In a toy airplane having a straiaht slot for receiving a wing, an integral wing element made oi sheet balsa wood permanently warped to predetermined form in which the ends thereof are given camber and the central is more or less flat and said end portions are obliquely inclined in opposite directions from said central portion at equal angles to give dihedral angle to said wing element. 

